自定义事件回调

选中节点高亮显示

#include <Windows.h>
#include <osg/Node>
#include <osg/Group>
#include <osg/Geode>
#include <osg/Switch>
#include <osgFX/Scribe>
#include <osgViewer/Viewer>
#include <osgDB/ReadFile>
#include <osgViewer/ViewerEventHandlers>

class PickHander : public osgGA::GUIEventHandler
{
public:
	virtual bool handle(const osgGA::GUIEventAdapter& ea, osgGA::GUIActionAdapter& aa) override
	{
		osgViewer::Viewer* viewer = dynamic_cast<osgViewer::Viewer*>(&aa);
		if (!viewer)
			return false;

		if (ea.getEventType() == osgGA::GUIEventAdapter::PUSH)
		{
			osgUtil::LineSegmentIntersector::Intersections intersections;
			if (viewer->computeIntersections(ea.getX(), ea.getY(), intersections))
			{
				osgUtil::LineSegmentIntersector::Intersection intersection = *intersections.begin();
				doUserOperations(intersection);
			}
		}

		return false;
	}

	void doUserOperations(const osgUtil::LineSegmentIntersector::Intersection& intersection)
	{
		osg::NodePath node_path = intersection.nodePath;
		for (auto itr = node_path.begin(); itr != node_path.end(); ++itr)
		{
			osg::Group* group = dynamic_cast<osg::Group*>(*itr);
			if (!group)
				continue;

			if (group->getName() != std::string("pick_node"))
				continue;

			osgFX::Scribe* scribe = dynamic_cast<osgFX::Scribe*>(group->getChild(1));
			if (!scribe)
				continue;

			bool enabled = scribe->getEnabled();
			scribe->setEnabled(!enabled);
		}
	}
};

void composeNodeFactory(osg::Node* node,osg::Group* parent)
{
	osg::ref_ptr<osg::Switch> group = new osg::Switch();
	group->setName("pick_node");

	osg::ref_ptr<osgFX::Scribe> scribe = new osgFX::Scribe();
	scribe->setWireframeColor(osg::Vec4(0.0, 0.0, 1.0, 1.0));
	scribe->setWireframeLineWidth(2.0);
	scribe->addChild(node);
	scribe->setEnabled(false);

	group->addChild(node);
	group->addChild(scribe);

	parent->addChild(group);
}

int main()
{
	osgViewer::Viewer viewer;

	osg::ref_ptr<osg::Group> group = new osg::Group();
	composeNodeFactory(osgDB::readNodeFile("avatar.osg"), group);
	composeNodeFactory(osgDB::readNodeFile("cessna.osgt"), group);

	viewer.setSceneData(group);
	viewer.addEventHandler(new PickHander());
	viewer.addEventHandler(new osgViewer::StatsHandler());
	viewer.setUpViewInWindow(100, 100, 500, 400);

	return viewer.run();
}